Method of producing lugged pottery



July 16, 1935. G. B. ZAHNISER, JR, ET AL 2,007,993

METHOD 0F PRODUCING LUGG'ED POTTERY Filed Sept. 14, 1934 Patented July16, 1935 METHOD OF PRODUCING LUGGED POTTERY George B. Zahniser, Jr., andJames M. Smith, Jr., New Castle, Pa.

Application September 14, 1934, Serial No. 743,956

, 3 Claims. (01. 25-156) In the manufacture of pottery receptacleshaving lugs, handles or the like, it has been customary toproduce thebody of the pottery receptacle according to one of several well known 5practices, to produce the lug, handle or the like as aseparate article,and, while there is still sufficient moisture in the two parts thusproduced, to afiixthe lug'or the like to the body of the receptacle. Thelugged receptacle is then fired, after which it maybe finished as bydecorating, glazing, etc., all of which operations are well understoodin the art.

This invention relatesparticularly to the manner' of producing andapplying'to the preformed 5 body of the pottery receptacle the lug,handle 'or the like. An object of the invention is to reduce the amountof hand operations required in the application of these parts to thepreformed bodies ofthe pottery receptacles; and to' thus make itpossible to produce more uniform articles at less cost.

The improvement is illustrated in the accompanying drawing in which Fig.1 is a view-in elevation of the preformed body of a cup;

Fig. 1a is a similar view ofa slightly modified form of preformed body;

Fig. 2 illustrates the step in the process according to which a lug moldis applied against the preformed body of the receptacle;

Fig. 3 is a detail view of halves;

Fig. 4 is a View in elevation of a cup produced in accordance with ourinvention;

Fig. 5 is a detail plan view showing the juncture between the handle andbody of the cup;

Figs. 6, 7 and 8 illustrate the prior art practice in accordance withwhich a preformed handle such as shown in Fig. 6 is cut to the propershape, as shown in Fig. 7, by the workman and applied to the cup asshown in Fig. 8.

The drawing illustrates the improvement as applied to the production ofcups; but it will become apparent in the course of the ensuingdescription that the change in the manufacture of cups set forth indetail is applicable likewise to pottery receptacles in general whichare to be provided with lugs, handles or the like. In the description,the term lug will, for the sake of simplicity, be employed as a generalterm of definition applying to a handle or similar part.

No change is contemplated in the manner of producing the body 0 of thepottery receptacle. It is customary in the manufacture of china cups,for instance, to form this body portion 0 from a one of the mold mixtureof plastic clay, silica and feldspar. The desired shape of cup may beobtained by a molding or pressing operation. Quite commonly the body isgiven a true and finished configuration by turning, as is Well known inthis art. Ashas been above mentioned, it is within the contemplation ofthe. invention that the body bepreformed in any suitable manner; and infact the same may be slip cast. i

The lugs heretofore have commonly been produced as separate articles,generally by slip casting. For instance, a slip having practicallythesame composition as the body of the cup, except for the increase in thewater content, is cast. in a plaster of Paris mold to provide a handleit such as shown in Fig. 6. But a slight additional amount of water isrequired to render the com position thus fluid when a small addition,say 1%, of sodium silicate is made to the composition. The plaster ofParis moldacts towithdraw the slight amount of additional water; and asthe fluidity of the composition depends upon this slight excess ofwater, the casting is soon firm enough to be handled. The cast handlesare then trimmed or cut by the workman using an;

arcuate blade, the handles being cut to'fit the rounded side of the cupbody as illustrated in Fig. 7. Skill and precision are required in thustrimming the blank to the correct shape h, and this is a source of highlabor costs in the manufacture of these articles.

In accordance with our improved practice, a lug mold m is appliedagainst the preformed body, as illustrated in Fig. 2, and the lug. isslip cast so as to unite with the body by pouring the slip into the mold711.. The detail view, Fig. 3, of one-half of this mold shows the sameprovided with a surface 9 shaped to lie snugly against the side of thecup. This surface merges with the adjacent side wall of the mold cavityl0; and as the slip penetrates to fill the entire mold cavity, the lugin the finished productmerges with the body 0. A core I l forms the ovalopening in the handle if this is the part which is tobe applied to thebody. The slip enters through a pouring opening 12. Dowels l3 or thelike may be employed for causing the two mold halves to accuratelyregister.

In order to give suflicient pressure to make the impression clear, thepipe p may be used for pouring this slip so as to increase the statichead. After the plaster of Paris mold m has absorbed sufiicient water toharden the lug or handle, the mold m is removed, and the cast lug orhandle smoothed off at the point where the pouring decorations and/orthe glazing, if applied to the opening [2 leaves a rough projection. Itwill be noted that this, the least finished portion of the casting, ison a lower and less conspicuous portion of the handle when the same iscast on a cup in the inverted position. There is no inherent reason whythe lug should not be cast against the cup when in upright positioninstead of inverted position, but we prefer the inverted manner shown.

It will be noted from Fig. 3 that the mold cavity 10 opens against theside of the body 0, so that when the slip is poured into the mold, thecast lug is in the course of this operation united with the preformedreceptacle. It may be found desirable in certain cases to provide thebody of the receptacle during the forming of the same,.

with an indentation to improve the adherence of the lug to the body.Such a preformed body with an indentation M is illustrated in Fig. 1a.When assembling the mold m with the body 0, the opening of the moldcavity is brought into registry with this indentation; and accordinglyin casting the lug the fluid slip fills the indentation, thus unitingthe lug and body. lhe indentation is, of course, not visible in the completed article. The latter, as shown in Fig. 4 and in greater detail inFig. 5. has a more finished appearancethan the product in which thehandle is shaped by hand, as illustrated in Figs. 6, 7 and 8. From Fig.it will be noted that the cast lug merges into the body of the articlein a way which cannot be readily duplicated, even by skilled workmen,when the lug h is trimmed to the shape It and then applied as a separatearticle to the body 0. v

After the mg or lugs have been applied to the receptacle, the same isfired in the usual manner. This improvement is not concerned with thisportion of the usual manufacturing procedure, Moreover, the finishing,such as the fired article, can be performed in accordance with usualpractice.

It will be apparent from theabove description that the inventioneliminates a troublesome hand-operation in the production of luggedpottery articles. The new procedure is dependable,

more expeditious, and results in reducing the labor costs in themanufacture of these articles. Moreover, the product has a pleasingappearance, and the elimination of the human element makes for greateruniformity in the shape and. appearance of the finished product.

While we have illustrated and described our improved method moreparticularly in connection with the production of cups, it is clear thatthis is merely illustrative of how the invention may be appliedgenerally to lugged pottery articles; and, therefore, it will beunderstood that our invention is not limited to the precise embodimentillustrated but may be otherwise embodied and practiced within the scopeof the following claims.

We claim:

1. In a method of manufacturing lugged pottery receptacles, the stepsconsisting of preforming the body of the pottery receptacle, applying alug mold against the preformed receptacle in such fashion as to bringthe cavity opening into registry with the place on the receptacledetermined upon for the lug, slip casting a lug, handle, or the like insaid mold to unite with the preformed receptacle, and firing the luggedreceptacle.

2. In a method of manufacturing lugged pottery receptacles, the stepsconsisting of preforming the body of the pottery receptacle, providingin registry with the place on the receptacle determined upon for the luga mold cavity of the desired conformation, slip casting therein a lug,handle or the like, and firing the lugged receptacle.

3. In a method of manufacturing lugged pottery receptacles, the stepsconsisting of preforming the body of the pottery receptacle with anindentation where the lug is to be joined thereto, applying a lug moldagainst the preformed receptacle with the mold cavity opening inregistry with said indentation, slip casting a lug, handle, or the likein said mold against the preformed receptacle uniting therewith, andfiring the lugged receptacle.

GEORGE B. ZAHNISER, JR. JAMES M. SMITH, JR.

